Young was a regular in the public gallery during Haddock's trial for the attempted murder of pub doorman Trevor Gowdy, and wore this mask to hide his face from the media as he went in and out of the Laganside court complex.

In spite of his public support for Haddock, Sunday Life understands Young was arrested in north Belfast on Friday morning and was last night still being quizzed by cops about the murder bid on his former friend.

Also being questioned was Darren Moore, who stood beside Haddock in the dock charged in relation to the attempted murder of Gowdy.

Moore - who has also been questioned about the UVF murder of former UDA commander Tommy English in 2000 - was eventually cleared of the attack on Gowdy.

A judge stayed the case against Moore after the doorman suffered a nervous breakdown in the witness box before Moore's lawyer could cross-examine him.

Special Branch agent Haddock was last night continuing to recover in the Royal Victoria Hospital after being shot six times in the body when he was lured to a meeting on the Doagh Road, Newtownabbey last Tuesday.

Loyalist sources have told Sunday Life that the attempt on Haddock's life was carried out with the full knowledge of the UVF's leadership.

According to those sources, the UVF's Shankill Road-based chief-of-staff gave the green light for the murder of Haddock.

And the loyalist paramilitary group's 'brigadier' in South East Antrim is believed to have given the nod to Haddock's would-be killers.

It is understood that cops have already spoken to Haddock as he recovers under armed guard in hospital.

They have not yet taken a full statement about the murder bid from the Special Branch informer, but it is understood that Haddock has been willing to identify the man who set him up for murder and the other men who joined him in the murder bid.

And he has told his family that they may have to leave Ulster if he now gives evidence against his attackers.

Sunday Life understands that three men were involved in the attempt on Haddock's life.

As he arrived at the arranged meeting place near Mossley Orange Hall last Tuesday, the man who had set up the meeting got out of front passenger seat of a car and started talking to Haddock.

While they were talking, it is believed a second man got out of the back of the car and opened fire on Haddock with a small calibre handgun with a fitted silencer.

The gunman fired six shots into Haddock's body before the two men then fled with their waiting driver.

Police involved in the investigation were yesterday carrying out further searches of properties in greater Belfast.

Two men continued to help them with their inquiries, a spokesman said.